Many characters make up the detailed plot and interact with the growing storyline. You'll be using Mega Man X for the entire game, along the way you'll meet up with all the characters, good and bad, listed below. Read on for detailed descriptions of each character.

- Mega Man X

X is the first reploid created by Dr. Light in the year 20XX. X is the first robot ever who could think for himself, as well as having his own feelings and emotions. Dr. Light had feared that the world may need a new champion, and so he created X. Once uncovered by Dr. Cain thirty years after X was in the capsule, he was amazed at X's capabilities and so Cain began to create a new race of robots - the Reploids. Unfortunately, some of these new reploids went "maverick" for some unknown reason and began to threat the existence of the human race. X feels that it is up to him to rid the world of the Mavericks and bring peace for both humans and reploids.

- Zero

Zero is a powerful reploid who's origins are shrouded in mystery. His current status is the new leader of the Maverick Hunters after his battle against the once-reploid Sigma. He joined up with X in the fight against the Mavericks and they soon became best friends and partners. Zero has confidence in X and can see X to be a powerful warrior against the Mavericks. He helps X out often during the game.

- Dr. Light

Dr. Light is the creator of X. His true reasons as to why he made X is not fully known, but it is known that he could not live until the day that X's capabilities and reliability could be confirmed. Dr. Cain was the first to discover Dr. Light's work and continued it for him. During the game, X will find special powerup capsules where a holographic image of Dr. Light will give X a new enhanced ability.

- Vile

Vile is Sigma's top commander of the Maverick army and a robot built specifically for war. He commands Sigma's vast army of Mavericks and is almost as big a threat as Sigma himself. He knows X and Zero are after him, but is confident that he will not lose to them. X will meet Vile more than once during the game before the final showdown.

- Sigma

Sigma is the leader of the Maverick army. He was originally designed to be the leader of the Maverick Hunters and seemed immune to whatever caused the robots to become maverick, but unfortunately he was so badly infected by the virus, that he took many of the Maverick Hunters to follow his army. He believed that the humans were inferior and should be destroyed. His ultimate plan was to build an entire civilization of Mavericks and began a new age without humans. Sigma is X and Zero's primary target, as without him the Mavericks would fall apart.